This study aims to describe the data structure and harmonisation process, explore data quality and define characteristics, treatment, and outcomes of patients across six federated antineutrophil ...cytoplasmic antibody-associated vasculitis (AAV) registries.
Through creation of the vasculitis-specific Findable, Accessible, Interoperable, Reusable, VASCulitis ontology, we harmonised the registries and enabled semantic interoperability. We assessed data quality across the domains of uniqueness, consistency, completeness and correctness. Aggregated data were retrieved using the semantic query language SPARQL Protocol and Resource Description Framework Query Language (SPARQL) and outcome rates were assessed through random effects meta-analysis.
A total of 5282 cases of AAV were identified. Uniqueness and data-type consistency were 100% across all assessed variables. Completeness and correctness varied from 49%-100% to 60%-100%, respectively. There were 2754 (52.1%) cases classified as granulomatosis with polyangiitis (GPA), 1580 (29.9%) as microscopic polyangiitis and 937 (17.7%) as eosinophilic GPA. The pattern of organ involvement included: lung in 3281 (65.1%), ear-nose-throat in 2860 (56.7%) and kidney in 2534 (50.2%). Intravenous cyclophosphamide was used as remission induction therapy in 982 (50.7%), rituximab in 505 (17.7%) and pulsed intravenous glucocorticoid use was highly variable (11%-91%). Overall mortality and incidence rates of end-stage kidney disease were 28.8 (95% CI 19.7 to 42.2) and 24.8 (95% CI 19.7 to 31.1) per 1000 patient-years, respectively.
In the largest reported AAV cohort-study, we federated patient registries using semantic web technologies and highlighted concerns about data quality. The comparison of patient characteristics, treatment and outcomes was hampered by heterogeneous recruitment settings.
Granulomatosis with polyangiitis (GPA) is an autoimmune disease with still unknown etiology. Recent studies indicate that neutrophils extra-cellular traps participate in the pathophysiology of GPA. ...This study investigates the levels of circulating NET formation markers and neutrophil-platelet interaction in patients with GPA.
We enrolled 40 GPA patients (20 in the active stage of the disease and 20 in remission). Twenty sex- and age-matched healthy subjects served as a control group. Serum/plasma levels of serine proteases, and histone-, myeloperoxidase-, proteinase-3 DNA complexes and sP-selectin were measured using ELISA or Luminex assays. Circulating platelet-neutrophil aggregates and neutrophils activation markers expression was measured by flow cytometry.
Patients in active stage of GPA had higher circulating levels of serine proteases, DNA-histone and myeloperoxidase -DNA complexes. In addition, platelet-neutrophil aggregates and sP-selectin were also elevated in this group. Platelet-neutrophil aggregates and myeloperoxidase -DNA complexes correlated positively with the disease activity score (BVAS).
NETs production and activation of platelets in GPA is supported by elevated myeloperoxidase-DNA complexes and platelet-neutrophil aggregates correlating positively with the disease activity score. This mechanism justifies laboratory measurements of myeloperoxidase-DNA complexes and plasma sP-selectin as biomarkers for studying GPA activity.
Granulomatosis with polyangiitis is a chronic systemic inflammation of small vessels characterized by circulating anti-proteinase 3 antibodies. MicroRNAs are short transcripts specifically inhibiting ...protein translation. Neutrophils can release extracellular vesicles (EVs). In this study, we characterized profile of microRNA trafficked by EVs in GPA. Fifty patients with GPA were enrolled in the study, 25 at acute phase and 25 in remission. EVs were isolated from the blood serum, characterized by their number, size distribution. Following unbiased screening for microRNA expression, differentially expressed candidates were measured by quantitative real-time PCR. Circulating DNA-myeloperoxidase complexes and apoptosis-related transcripts in peripheral blood neutrophils were quantified. We identified four differentially expressed microRNAs from EVs in granulomatosis with polyangiitis (GPA). MirRs-223-3p, 664a-3p, and 200b-3p were overexpressed and miR-769-5p suppressed in the disease. A distinction between GPA and healthy controls was the best for miR-223-3p, whereas miR-664a-3p discriminated between active vs. remission of GPA. Correct classification of the disease based on multivariate discriminant analysis was between 92% for acute phase and 85% for all study participants. Bioinformatics tools identified genes transcripts potentially targeted by the microRNAs belonging to pathways of focal adhesion, mTOR signaling and neutrophil extracellular traps formation. Two microRNAs positively correlating with the disease activity were involved in neutrophil extracellular traps formation and apoptosis inhibition. A comprehensive characteristics of microRNAs trafficked in bloodstream inside EVs correlates well with our understanding of the mechanisms of GPA and suggests the importance of EVs in progression of the disease.
ANCA-associated vasculitides (AAV) are a heterogeneous group of rare diseases with unknown aetiology and the clinical spectrum ranging from life-threatening systemic disease, through single organ ...involvement to minor isolated skin changes. Thus, there is an unmet need for phenotype identification, especially among patients with granulomatosis with polyangiitis (GPA). Patients with microscopic polyangiitis (MPA) seem to be clinically much more uniform. Recently, three subcategories of AAV have been proposed and described as non-severe AAV, severe PR3-AAV, and severe MPO-AAV.
In line with these attempts, we decided to use an unbiased approach offered by latent class analysis (LCA) to subcategorise GPA and MPA in a large cohort of Polish AAV patients included in a multicentre POLVAS registry.
LCA of our AAV group identified a four-class model of AAV, including previously proposed three subphenotypes and revealing a fourth (previously not described) clinically relevant subphenotype. This new subphenotype includes only GPA patients, usually diagnosed at a younger age as compared to other groups, and characterised by multiorgan involvement, high relapse rate, relatively high risk of death, but no end-stage kidney disease.
Based on multiple clinical and serological variables, LCA methodology identified 4-class model of AAV. This newly described fourth class of AAV may be of clinical relevance and may require prompt diagnosis and aggressive treatment due to the multiorgan involvement, high risk of relapse and marked mortality among these relatively young GPA subjects.
Objective. To characterize the eosinophilic granulomatosis with polyangiitis (EGPA) population from the POLVAS registry depending on ANCA status and diagnosis onset, including their comparison with ...the granulomatosis with polyangiitis (GPA) subset with elevated blood eosinophilia (min. 400/μl) (GPA HE) to develop a differentiating strategy. Methods. A retrospective analysis of the POLVAS registry. Results. The EGPA group comprised 111 patients. The ANCA-positive subset (n = 45 40.54%) did not differ from the ANCA-negative one in clinics. Nevertheless, cardiovascular manifestations were more common in ANCA-negative patients than in those with anti-myeloperoxidase (MPO) antibodies (46.97% vs. 26.92%, p = 0.045). Patients diagnosed before 2012 (n = 70 63.06%) were younger (median 41 vs. 49 years, p <0.01), had higher blood eosinophilia at diagnosis (median 4,946 vs. 3,200/μl, p <0.01), and more often ear/nose/throat (ENT) and cardiovascular involvement. GPA HE comprised 42 (13.00%) out of 323 GPA cases with reported blood eosinophil count. Both GPA subsets had a lower prevalence of respiratory, cardiovascular, and neurologic manifestations but more often renal and ocular involvement than EGPA. EGPA also had cutaneous and gastrointestinal signs more often than GPA with normal blood eosinophilia (GPA NE) but not GPA HE. The model differentiating EGPA from GPA HE, using ANCA status and clinical manifestations, had an AUC of 0.92, sensitivity of 96%, and specificity of 95%. Conclusion. Cardiovascular symptoms were more prevalent in the ANCA-negative subset than in the MPO-ANCA-positive one. Since EGPA and GPE HE share similarities in clinics, diagnostic misleading may result in an inappropriate therapeutic approach. Further studies are needed to optimize their differentiation and tailored therapy, including biologics.
Patients with granulomatosis with polyangiitis (GPA) show increased tendency toward thromboembolic phenomena in exacerbation of their disease.
The aim of the study was to evaluate thrombin generation ...potential and fibrinolytic plasma activity in patients with GPA, both in exacerbation and in remission.
We included 38 patients with GPA: 18 with exacerbated GPA and 20 in remission. The control group included 39 healthy participants matched for age and sex. Plasma thrombogenic potential was assessed using calibrated automated thrombography. Plasma fibrinolytic potential was assessed using clot lysis time (CLT). We also measured levels of inflammatory markers, thrombomodulin, and fibrinolysis proteins in all participants.
In the whole group of patients with GPA, endogenous thrombin potential was higher by about 25% (P <0.001), while CLT was lower by about 20% (P = 0.02) when compared with controls. The endogenous thrombin potential was higher, the CLT lower, and the levels of thrombomodulin and inflammation markers (C‑reactive protein, fibrinogen, factor VIII) higher both in patients with exacerbation and in remission than in the control group; no such differences were noted when comparing those with exacerbation and those in remission, however. The only parameter that differentiated patients with GPA exacerbation from those in remission was the D‑dimer level (median interquartile range, 1151 597.2-2468.7 ng/ml vs 340.4 255.1-500.7 ng/ml; P <0.001), a marker of lysis of intravascularly formed fibrin.
Patients with GPA show an increased prothrombotic state, regardless of the disease phase. This is probably related to ongoing low-grade inflammation and endothelial injury. Large clinical studies are required to address the need for, and appropriate type of, antithrombotic prophylaxis during the course of GPA.
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